GEO Exam 3

FRONTS

Low pressure systems

Stationary Fronts

Cold and warm air masses not advancing on each other

Cold Fronts

Cold air mass advances on warm air mass HIGH INTENSITY PRECIPITATION

Warm Fronts

Warm advance on cold air LOW INTENSITY PRECIPITATION

Occluded Fronts

Cold Front overtakes wwarm front

Ridges and Troughs

Movements of warm and cold air masses causing dynamic surface high and low pressure systems

Convergence upwind side of trough

anticyclone at surface (dynamic high pressure)

Divergence downwind side of trough

cyclone at surface (dynamic low pressure)

Why would we get freezing rain?

Warm front goes thorugh cold air that can re freeze and turn into sleet

Requirements for Thunderstorms

Uplift

Instability

Moist air

Air mass thunderstorms

convection uplift causes updrafts (develop late afternoon on warm humid day)

Downdrafts

caused by precipitation pulling air down from higher in troposphere

Self-propagating Thunderstorms

Longer lived

uplift is initated in the warm sector of a mid-latitude cyclone

Severe weather?

Winds >93 km/hr

Hailstones larger than 2.5cm

Lightning

Rapid discharge of electricity

80% is cloud-to-cloud lightning, and 20% is cloud-to-ground lightning

Thunder

Rapid heating to 27,700 C causes explosive expansion of air

Hail

forms when strong updrafts lift falling ice back up to colder air

Tornadoes

rapidly rotating column of air in touch with the ground

Common in the central part of the US

RELATIVELY SMALL & SHORT-LIVED

Universe

estimated to be 13.8 billion yrs old based on age of stars and rate of expansion

Earth

4.54 billion yrs old based on radiometric datons of uranium in meteorites

oldest mineral

found on Earth is a 4.4 billion yr old ZIRCON found in quartile in Australia

oldest rock

Found on Earth is a 4.03 billion yr old gneiss from Canada

PRECAMBRIAN

First life on Earth

Oxygenation of the atmosphere

1st Eukaryotic organisms

1st animals

Paleozoic “old life”

First land plants and animals

Age of most coal deposits (from plant remains buried in wetlands)

Mesozoic “middle life”

Appearance and extinction of dinosaurs

First birds and flowering plants

Age of most oil and natural gas deposits (algae, Plankton, bacteria, plant remains)

Cenozoic Era “new life”

Flowering plants and mammals dominate

Rise of hominins

Minerals requirement

Solid

Naturally Occurring

Inorganic

Crystalline

On a topographic, map, the more widely spaced the contour lines are the

gentler the slope

You are given a map with a representative fraction (RF) of 1:62,500. You measure a distance of 8.11 inches between two points on the map. What is the real-world horizontal distance between the points in miles? Note that there are 5,280 feet in a mile. (Give your answer to the nearest whole number, e.g., 13)

9 km

The magnetic declination for La Crosse, WI is approximately _________.

1 West or -1

When using a compass navigate to a feature in the field, it is best to ___________.

Set the travel direction by rotating your body with the compass until the magnetized needle resides within the orienting arrow

The amount of vertical change between adjacent contour lines on a topographic map is called the _____________

Contour interval

You are given a map with a representative fraction (RF) of 1:62,500. You measure a distance of 8.11 inches between two points on the map. What is the real-world horizontal distance between the points in miles? Note that there are 5,280 feet in a mile. (Give your answer to the nearest whole number, e.g., 13)

8

What is the elevation of point B on the topographic map? (Give just the number, e.g., 580)

760

What is the aspect of point B on the topographic map? Note: North is at the top of the map.

Southeast

The compass in the image is sighted on an object in the field. What is the true bearing to the object? Note that the markings on the rotating bezel are in 2° increments. Provide your answer as a whole number without a degree symbol.

352

A scale of 1:20,000 on a topographic map indicates that _____________________.

1 unit of measure on the map is equivalent too 20,000 units real world